Remove need for explicit backend typealias (using extensions) and make backend configurable via SCUI_BACKEND env var when running examples

Author: stackotter

Examples/Package.swift

@@ -1,8 +1,9 @@
 // swift-tools-version:5.6
 
+import Foundation
 import PackageDescription
 
-let backend = "GtkBackend"
+let backend = ProcessInfo.processInfo.environment["SCUI_BACKEND"] ?? "GtkBackend"
 
 let exampleDependencies: [Target.Dependency] = [
     "SwiftCrossUI",

Examples/Sources/ControlsExample/ControlsApp.swift

@@ -9,8 +9,6 @@ class ControlsState: Observable {
 
 @main
 struct ControlsApp: App {
-    typealias Backend = SelectedBackend
-
     let identifier = "dev.stackotter.Controls"
 
     let state = ControlsState()

Examples/Sources/CounterExample/CounterApp.swift

@@ -7,8 +7,6 @@ class CounterState: Observable {
 
 @main
 struct CounterApp: App {
-    typealias Backend = SelectedBackend
-
     let identifier = "dev.stackotter.CounterApp"
 
     let state = CounterState()

Examples/Sources/GreetingGeneratorExample/GreetingGeneratorApp.swift

@@ -8,8 +8,6 @@ class GreetingGeneratorState: Observable {
 
 @main
 struct GreetingGeneratorApp: App {
-    typealias Backend = SelectedBackend
-
     let identifier = "dev.stackotter.GreetingGenerator"
 
     let state = GreetingGeneratorState()

Examples/Sources/NavigationExample/NavigationApp.swift

@@ -23,8 +23,6 @@ class NavigationAppState: Observable {
 
 @main
 struct NavigationApp: App {
-    typealias Backend = SelectedBackend
-
     let identifier = "dev.stackotter.NavigationApp"
 
     let state = NavigationAppState()

Examples/Sources/RandomNumberGeneratorExample/RandomNumberGeneratorApp.swift

@@ -27,8 +27,6 @@ enum ColorOption: String, CaseIterable {
 
 @main
 struct RandomNumberGeneratorApp: App {
-    typealias Backend = SelectedBackend
-
     let identifier = "dev.stackotter.RandomNumberGeneratorApp"
 
     let state = RandomNumberGeneratorState()

Examples/Sources/SplitExample/SplitApp.swift

@@ -30,8 +30,6 @@ class SplitAppState: Observable {
 
 @main
 struct SplitApp: App {
-    typealias Backend = SelectedBackend
-
     let identifier = "dev.stackotter.SplitApp"
 
     let state = SplitAppState()

Examples/Sources/SpreadsheetExample/SpreadsheetApp.swift

@@ -25,8 +25,6 @@ class SpreadsheetState: Observable {
 
 @main
 struct SpreadsheetApp: App {
-    typealias Backend = SelectedBackend
-
     let identifier = "dev.stackotter.SpreadsheetApp"
 
     let state = SpreadsheetState()

Examples/Sources/StressTestExample/StressTestApp.swift

@@ -26,8 +26,6 @@ class StressTestState: Observable {
 
 @main
 struct StressTestApp: App {
-    typealias Backend = SelectedBackend
-
     let identifier = "dev.stackotter.StressTestApp"
 
     let state = StressTestState()

Examples/Sources/WindowingExample/WindowingApp.swift

@@ -9,8 +9,6 @@ class WindowingAppState: Observable {
 
 @main
 struct WindowingApp: App {
-    typealias Backend = SelectedBackend
-
     let identifier = "dev.stackotter.WindowPropertiesApp"
 
     let state = WindowingAppState()

README.md

@@ -41,6 +41,7 @@ Here's a simple example app demonstrate how easy it is to get started with Swift
 
 ```swift
 import SwiftCrossUI
+// Import whichever backend you need
 import GtkBackend
 
 class CounterState: Observable {
@@ -49,9 +50,9 @@ class CounterState: Observable {
 
 @main
 struct CounterApp: App {
-    // An experimental AppKit backend is also available when on macOS (try AppKitBackend)
-    // There's also a Qt5 backend (QtBackend) available when qt5 is installed
-    typealias Backend = GtkBackend
+    // Optionally, you can explicitly select which imported backend to use (this is done for
+    // you if only one backend is imported).
+    //  typealias Backend = GtkBackend
 
     let identifier = "dev.stackotter.CounterApp"
 
@@ -74,26 +75,33 @@ To run this example, run these commands:
 
 ```sh
 git clone https://github.com/stackotter/swift-cross-ui
-cd swift-cross-ui
+cd swift-cross-ui/Examples
 swift run CounterExample
 ```
 
-To see all of the examples, run these commands:
+### Other examples
 
-```sh
-swift run CounterExample
-swift run RandomNumberGeneratorExample
-swift run WindowingExample
-swift run GreetingGeneratorExample
-swift run FileViewerExample
-swift run NavigationExample
-swift run SpitExample
-swift run StressTestExample
-swift run SpreadsheetExample
-swift run ControlsExample
-```
+A few examples are included with SwiftCrossUI to demonstrate some of its basic features;
+
+- `CounterExample`, a simple app with buttons to increase and decrease a count.
+- `RandomNumberGeneratorExample`, a simple app to generate random numbers between a minimum and maximum.
+- `WindowingExample`, a simple app showcasing how ``WindowGroup`` is used to make multi-window apps and
+  control the properties of each window.
+- `GreetingGeneratorExample`, a simple app demonstrating dynamic state and the ``ForEach`` view.
+- `FileViewerExample`, an app showcasing integration with the system's file chooser.
+- `NavigationExample`, an app showcasing ``NavigationStack`` and related concepts.
+- `SplitExample`, an app showcasing sidebar-based navigation with multiple levels.
+- `StressTestExample`, an app used to test view update performance.
+- `SpreadsheetExample`, an app showcasing tables.
+- `ControlsExample`, an app showcasing the various types of controls available.
 
-All examples use the `GtkBackend` but can easily be updated to test out other backends.
+### Running examples on other backends
+
+All examples use `GtkBackend` by default but you can override this using the `SCUI_BACKEND` environment variable like so;
+
+```
+SCUI_BACKEND=QtBackend swift run CounterExample
+```
 
 ## Documentation
 

Sources/AppKitBackend/AppKitBackend.swift

@@ -1,6 +1,10 @@
 import AppKit
 import SwiftCrossUI
 
+extension App {
+    public typealias Backend = AppKitBackend
+}
+
 public struct AppKitBackend: AppBackend {
     public typealias Window = NSWindow
     public typealias Widget = NSView

Sources/CursesBackend/CursesBackend.swift

@@ -2,6 +2,10 @@ import Foundation
 import SwiftCrossUI
 import TermKit
 
+extension App {
+    public typealias Backend = CursesBackend
+}
+
 public final class CursesBackend: AppBackend {
     public typealias Window = RootView
     public typealias Widget = TermKit.View

Sources/GtkBackend/GtkBackend.swift

@@ -3,6 +3,10 @@ import Foundation
 import Gtk
 import SwiftCrossUI
 
+extension App {
+    public typealias Backend = GtkBackend
+}
+
 extension SwiftCrossUI.Color {
     public var gtkColor: Gtk.Color {
         return Gtk.Color(red, green, blue, alpha)

Sources/LVGLBackend/LVGLBackend.swift

@@ -3,6 +3,10 @@ import Foundation
 import LVGL
 import SwiftCrossUI
 
+extension App {
+    public typealias Backend = LVGLBackend
+}
+
 public final class LVGLBackend: AppBackend {
     public class Widget {
         private var createWithParent: (LVObject) -> LVObject

Sources/QtBackend/QtBackend.swift

@@ -2,6 +2,10 @@ import Foundation
 import Qlift
 import SwiftCrossUI
 
+extension App {
+    public typealias Backend = QtBackend
+}
+
 // TODO: Remove default padding from QBoxLayout related widgets.
 // TODO: Fix window size code, currently seems to get pretty ignored.
 

Sources/SwiftCrossUI/SwiftCrossUI.docc/Examples.md

@@ -4,7 +4,7 @@ An overview of the examples included with SwiftCrossUI.
 
 ## Overview
 
-A few examples are included with SwiftCrossUI to demonstrate some of it's basic features. These examples are:
+A few examples are included with SwiftCrossUI to demonstrate some of its basic features;
 
 - `CounterExample`, a simple app with buttons to increase and decrease a count.
 - `RandomNumberGeneratorExample`, a simple app to generate random numbers between a minimum and maximum.
@@ -18,16 +18,8 @@ A few examples are included with SwiftCrossUI to demonstrate some of it's basic
 - `SpreadsheetExample`, an app showcasing tables.
 - `ControlsExample`, an app showcasing the various types of controls available.
 
-To run an example, either select the example under schemes at the top of the window (in Xcode), or run one of the following commands (if using a terminal):
+To run an example, either select the example under schemes at the top of the window (in Xcode), or run it from the command line like so:
+
 ```
-swift run CounterExample
-swift run RandomNumberGeneratorExample
-swift run WindowingExample
-swift run GreetingGeneratorExample
-swift run FileViewerExample
-swift run NavigationExample
-swift run SpitExample
-swift run StressTestExample
-swift run SpreadsheetExample
-swift run ControlsExample
+swift run ExampleToRun
 ```